Method and device for processing encoded video data, and method and device for generating encoded video data

ABSTRACT

Disclosed are a coded video data processing method and apparatus which consider a random access, and a coded video data generating method and apparatus which consider a random access. The coded video data processing method includes obtaining a bitstream of coded video data, obtaining metadata information used for video-processing of pictures having a decoding order after a random access point picture in the bitstream, and performing video-processing on decoded video data among the pictures having the decoding order after the random access point picture, based on the metadata information.

TECHNICAL FIELD

The present invention relates to a coded video data processing methodand apparatus, and a coded video data generating method and apparatus.

BACKGROUND ART

Since hardware capable of reproducing and storing high-resolution orhigh-quality video contents have been developed and popularized, a videocodec capable of efficiently coding or decoding high-resolution orhigh-quality video contents is in high demand. A typical video codeccodes video using limited coding schemes based on tree-structure codingunits.

Video data of the spatial domain is transformed into coefficients of thefrequency domain by using frequency transformation. The video codecsplits an image into predetermined-sized blocks for fast frequencytransformation, and performs discrete cosine transformation (DCT) oneach block to code block-unit frequency coefficients. To removeredundancy between color images, typical compression systems performblock-based prediction. The typical compression systems generateparameters used for video coding and decoding, in units of pictures.

DETAILED DESCRIPTION OF THE INVENTION Technical Problem

The present invention provides a coded video data processing method andapparatus which consider a random access, and a coded video datagenerating method and apparatus which consider a random access.Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

Technical Solution

According to an aspect of an embodiment, a coded video data processingmethod includes obtaining a bitstream of coded video data, obtainingmetadata information used for video-processing of pictures having adecoding order after a random access point picture in the bitstream, andperforming video-processing on decoded video data among the pictureshaving the decoding order after the random access point picture, basedon the metadata information.

The obtaining of the metadata information may include obtaining metadataidentification information corresponding to the metadata informationfrom a predetermined location in the bitstream, and obtaining themetadata information mapped to the obtained metadata identificationinformation, from a metadata information database.

The coded video data processing method may further include obtaining themetadata information database via a channel different from a channel viawhich the bitstream is obtained.

The obtaining of the metadata information may include obtaining themetadata information based on a location of the random access pointpicture in the bitstream and a location of a scene cut of a sceneincluding one or more pictures having a decoding order after the randomaccess point picture.

The obtaining of the metadata information may include, if the randomaccess point picture and decodable leading pictures belong to a samescene, obtaining metadata information of the scene to which the randomaccess point picture and the decodable leading pictures belong, based ona location of a first decodable leading picture in a display order.

The obtaining of the metadata information may include, if the randomaccess point picture and decodable leading pictures belong to differentscenes, obtaining metadata information of the scene to which the randomaccess point picture belongs and metadata information of the scene towhich the decodable leading pictures belong, based on a location of therandom access point picture and a location of a first decodable leadingpicture in a display order.

The location of the scene cut may correspond to a location of a firstpicture in a display order among pictures belonging to each scene.

According to another aspect of an embodiment, a coded video datagenerating method includes coding video data, generating metadatainformation used for video-processing of pictures having a decodingorder after a random access point picture, and generating a bitstream ofthe coded video data, the bitstream including the metadata informationor metadata identification information corresponding to the metadatainformation.

The generating of the bitstream may include generating the bitstream byinserting the metadata identification information into a predeterminedlocation in the bitstream.

The coded video data generating method may further include transmittingthe bitstream including the metadata identification information, and ametadata information database including the generated metadatainformation, via different channels.

The generating of the bitstream may include generating the bitstream byinserting the metadata information into a location of the random accesspoint picture and a location of a scene cut of a scene including one ormore pictures having a decoding order after the random access pointpicture.

The generating of the bitstream may include, if the random access pointpicture and decodable leading pictures belong to a same scene,generating the bitstream by inserting metadata information of the sceneto which the random access point picture and the decodable leadingpictures belong, into a location of a first decodable leading picture ina display order.

The generating of the bitstream may include, if the random access pointpicture and decodable leading pictures belong to different scenes,generating the bitstream by inserting metadata information of the sceneto which the random access point picture belongs, into a location of therandom access point picture, and inserting metadata information of thescene to which the decodable leading pictures belong, into a location ofa first decodable leading picture in a display order.

The location of the scene cut may correspond to a location of a firstpicture in a display order among pictures belonging to each scene.

According to another aspect of an embodiment, a non-transitorycomputer-readable recording medium has recorded thereon a computerprogram for executing the coded video data processing method or thecoded video data generating method.

According to another aspect of an embodiment, a video data processingapparatus includes a bitstream obtainer for obtaining a bitstream ofcoded video data, a video decoder for decoding the bitstream, and avideo processor for obtaining metadata information used forvideo-processing of pictures having a decoding order after a randomaccess point picture in the bitstream, and performing video-processingon the decoded video data among the pictures having the decoding orderafter the random access point picture, based on the metadatainformation.

The video processor may obtain metadata identification informationcorresponding to the metadata information from a predetermined locationin the bitstream, and obtain the metadata information mapped to theobtained metadata identification information, from a metadatainformation database.

The video processor may obtain the metadata information based on alocation of the random access point picture in the bitstream and alocation of a scene cut of a scene including one or more pictures havinga decoding order after the random access point picture.

According to another aspect of an embodiment, a video data generatingapparatus includes a video coder for coding video data and generatingmetadata information used for video-processing of pictures having adecoding order after a random access point picture, and a bitstreamgenerator for generating a bitstream of the coded video data, thebitstream including the metadata information or metadata identificationinformation corresponding to the metadata information.

The bitstream generator may generate the bitstream by inserting themetadata information into a location of the random access point pictureand a location of a scene cut of a scene including one or more pictureshaving a decoding order after the random access point picture.

Advantageous Effects of the Invention

A video bitstream may be appropriately processed even when a randomaccess has occurred.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a video data processing system.

FIG. 2A is a schematic diagram for describing video data.

FIG. 2B is a schematic diagram for describing coded video data.

FIG. 3A is a block diagram of a video data generating apparatusaccording to an embodiment.

FIG. 3B is a block diagram of a video data processing apparatusaccording to an embodiment.

FIG. 4 is a schematic diagram for describing a method of generating andprocessing a bitstream of coded video data by using metadataidentification information, according to an embodiment.

FIGS. 5A and 5B are tables showing message formats for transmittingmetadata identification information.

FIG. 6A is a schematic diagram for describing a method of generating andprocessing a bitstream of coded video data in consideration of anoptimal location of metadata information in the video bitstream,according to an embodiment.

FIG. 6B is a schematic diagram for describing a method of generating andprocessing a bitstream of coded video data in consideration of anoptimal location of metadata information in the video bitstream,according to another embodiment.

FIG. 6C is a schematic diagram for describing a method of generating andprocessing a bitstream of coded video data in consideration of anoptimal location of metadata information in the video bitstream,according to another embodiment.

FIG. 7A is a flowchart of a coded video data generating method accordingto an embodiment.

FIG. 7B is a flowchart of a coded video data processing method accordingto an embodiment.

BEST MODE

According to an aspect of an embodiment, a coded video data processingmethod includes obtaining a bitstream of coded video data, obtainingmetadata information used for video-processing of pictures having adecoding order after a random access point picture in the bitstream, andperforming video-processing on decoded video data among the pictureshaving the decoding order after the random access point picture, basedon the metadata information.

MODE OF THE INVENTION

Hereinafter, the present invention will be described in detail byexplaining embodiments of the invention with reference to the attacheddrawings. The invention may, however, be embodied in many differentforms and should not be construed as being limited to the embodimentsset forth herein; rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey theconcept of the invention to one of ordinary skill in the art.

It will be understood that the terms “comprises” and/or “comprising”,when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof.

It will be further understood that, although the terms first, second,third, etc., may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection.

In the following description, features well-known to one of ordinaryskill in the art will not be described in detail.

FIG. 1 is a block diagram of a video data processing system 10.

Referring to FIG. 1, the video data processing system 10 may include avideo data generating apparatus 100 and a video data processingapparatus 200.

The video data generating apparatus 100 may be a video coding apparatus.The video data generating apparatus 100 may generate coded video data bycoding input video, i.e., video data.

The video data processing apparatus 200 may be a video decodingapparatus. The video data processing apparatus 200 may generate decodedvideo data by decoding the coded video data.

The video data generating apparatus 100 may transmit a bitstream of thecoded video data (hereinafter referred to as a video bitstream) to thevideo data processing apparatus 200, and the video data processingapparatus 200 may receive the video bitstream.

FIG. 2A is a schematic diagram for describing video data.

The video data is a sequence of video frames, i.e., pictures. The videodata is called a video sequence.

A group of pictures (GOP) refers to a sequence of one or more picturesamong pictures arranged in a display order.

A picture is a sequence of video blocks, i.e., largest coding units(LCUs) or coding tree units (CTUs). A video block may have a luminancecomponent and a chroma component.

A video coding apparatus may divide a picture into a plurality ofslices. In this case, each slice may be an I slice, a P slice, or a Bslice. The I slice refers to a slice predicted using an intra predictionmode, the P slice refers to a slice predicted using an inter predictionmode, and the B slice refers to a slice predicted using a bi-directionalinter prediction mode.

Referring to FIG. 2A, the video data includes a plurality of picturesfrom a first picture to an eighth picture. The pictures included in thevideo data may be sequential pictures arranged in a display order. Thepictures from the first picture to the fourth picture belong to a firstGOP, and the pictures from the fifth picture to the eighth picturebelong to a second GOP.

An arbitrary picture may be divided into a plurality of slices, and eachslice may include a plurality of video blocks. Referring to FIG. 2A, thethird picture may be divided into a first slice and a second slice, andeach slice may include a plurality of video blocks, i.e., LCUs.

For video coding, each of the video data, the GOPs, the pictures, theslices, and coding units (CUs) may be associated with syntax dataindicating video coding attributes. A video decoding apparatus may usethe syntax data to decode the video data. The syntax data is a syntaxstructure including syntax elements, and may be regarded as a parameterset. For example, the high efficiency video coding (HEVC) standarddefines parameter sets such as a video parameter set (VPS), a sequenceparameter set (SPS), a picture parameter set (PPS), and an adaptiveparameter set (APS).

FIG. 2B is a schematic diagram for describing coded video data.

The coded video data is a sequence of pictures arranged in a decodingorder or a coding order. The coded video data is also called a codedvideo sequence.

Referring to FIG. 2B, the coded video data may include a plurality ofpictures from a first picture to an eighth picture. The picturesincluded in the coded video data may be sequential pictures arranged ina decoding order. That is, since the coded video data is a sequence ofpictures arranged not in a display order but in a decoding order, asillustrated in FIG. 2B, orders of the fifth picture and the sixthpicture may differ from the orders of the fifth picture and the sixthpicture in the video data of FIG. 2A. In other words, the sixth picturemay be decoded before the fifth picture.

Referring to FIG. 2B, an arbitrary picture may correspond to an accessunit. The access unit may include a plurality of network abstractionlayer (NAL) units, and include a coded picture. The NAL units may bedivided into video coding layer (VCL) NAL units and non-VCL NAL units.The VCL NAL units may include data of slices included in one picture ofvideo data. The non-VCL units may include information other than thedata of the slices, e.g., a parameter set.

Referring to FIG. 2B, the third picture is configured as a sequence ofheaders and NAL units. Accordingly, a bitstream of the coded video data,i.e., a video bitstream, may be regarded as a sequence of a plurality ofaccess units and, more particularly, a sequence of a plurality of NALunits arranged in a decoding order.

The video data generating apparatus 100 according to an embodiment ofthe present invention may include metadata information in the videobitstream. The video data processing apparatus 200 according to anembodiment of the present invention may obtain the metadata informationfrom the video bitstream, and perform a video process for display, ondecoded video data. The metadata information is information used for avideo process, and refers to data capable of increasing video qualityand applicable to the decoded video data to correspond to originalvideo. For example, the metadata information may be information about ascene, e.g., information about a scene cut, scene classification, acolor space of contents, or a color volume.

Each piece of the metadata information may include identificationinformation. When two pieces of the metadata information having the sameidentification information are transmitted, the currently transmittedmetadata information may partially update or entirely replace thepreviously transmitted metadata information. The metadata informationmay include information for cancelling the previously transmittedmetadata information. The metadata information may include informationabout how long the metadata information is to be applied. The metadatainformation may include one or more parameters including predeterminedvalues or conditions applicable when the metadata information is usedfor a video process.

The metadata information may be included in a supplemental enhancementinformation (SEI) message or a SEI NAL unit, and thus inserted into thevideo bitstream. The metadata information may be inserted into astarting part of each scene, and applied to a video processcorresponding to a plurality of pictures included in the scene. In thiscase, when a random access has occurred in a part other than a startingpart of any scene, since the metadata information of the scene is notpresent, video quality may be reduced.

To prevent loss of metadata information of each scene even when a randomaccess has occurred, the metadata information of a scene to which eachpicture belongs may be included in the locations of all picturesincluded in the video bitstream. However, this method may cause overheadin terms of a bitrate. Alternatively, the metadata information of eachpicture included in the received video bitstream may be checked andstored in memory by analyzing every part of the video bitstream, andused for a video process. However, this method is not easily applicableto real-time streaming, but is applicable only when the video bitstreamis completely received.

A description is now given of a method of generating and processing avideo bitstream including metadata information, in consideration of acase where a random access has occurred.

FIG. 3A is a block diagram of the video data generating apparatus 100according to an embodiment. It will be understood by one of ordinaryskill in the art that the video data generating apparatus 100 mayinclude general-use hardware elements in addition to elementsillustrated in FIG. 3A.

Referring to FIG. 3A, the video data generating apparatus 100 mayinclude a video coder 110 and a bitstream generator 130.

The video coder 110 may code video data. The video coder 110 maygenerate coded video data in a coding order by coding video input to thevideo data generating apparatus 100.

The video coder 110 may generate metadata information applicable todecoded video data when the coded video data is decoded and thenvideo-processed by the video data processing apparatus 200. The metadatainformation may be prepared in such a manner that pictures having adecoding order after a random access point may be decoded and thenvideo-processed even when a random access to the coded video data hasoccurred. In this case, the random access refers to, for example, a casewhere pieces of the coded video data are not sequentially decoded anddisplayed but decoding and displaying points are skipped or videosplicing is performed.

In other words, the video coder 110 may generate metadata information tobe inserted into a starting part of each scene and used for a videoprocess, or metadata information used for video-processing of pictureshaving a decoding order after a random access point picture.

The random access point picture refers to a picture of a point when arandom access has occurred. An intra random access point (IRAP) picturecapable of serving as a random-accessible random access point is thefirst picture of a video bitstream in a decoding order when a randomaccess has occurred, and may include only I slices. The RAP picture maybe a clean random access (CRA) picture, a broken link access (BLA)picture, or an instantaneous decoding refresh (IDR) picture.

The CRA picture is a picture capable of serving as a random access pointwhen a group of pictures (GOP) has an open structure. Since the CRApicture is an RAP picture, the CRA picture includes only I slices andmay be the first or middle picture of the video bitstream in a decodingorder. When the video bitstream is cut or lost or pictures are splicedand thus a random access has occurred in the CRA picture, precedingpictures having a decoding order before the CRA picture becomeunavailable. When the preceding pictures capable of serving as referencepictures of leading pictures are unavailable, the leading picturesreferring to the unavailable pictures may not be normally decoded.

The BLA picture serves as a random access point when coded pictures arespliced or the video bitstream is cut, and refers to a picture locatedin the middle of the video bitstream. The BLA picture has functions andproperties similar to those of the CRA picture. However, if a randomaccess has occurred, since the BLA picture is regarded as the beginningof a new sequence, unlike the CRA picture, when the BLA picture isreceived by a decoder, all video parameter information may be receivedagain. The BLA picture may be determined by the video coding apparatus100, or an external apparatus having received the video bitstream fromthe video coding apparatus 100 may change the CRA picture into the BLApicture. For example, when video bitstreams are spliced, the externalapparatus having received the video bitstreams may change the CRApicture into the BLA picture and transmit the video bitstreams to thevideo decoding apparatus 200 for decoding the video bitstreams, In thiscase, video parameter information may also be newly provided from theexternal apparatus to the video decoding apparatus 200.

To prevent loss of metadata information of each scene, which is used fora video process, even when a random access has occurred in the videodata processing apparatus 200, the video coder 110 may generate metadataidentification information to be included in the locations of allpictures belonging to each scene of the video bitstream.

The bitstream generator 130 may generate a bitstream of the coded videodata, which includes the metadata information. The bitstream generator130 may generate the video bitstream including the metadata informationby inserting the metadata information into a starting part of eachscene, or inserting the metadata information into an appropriatelocation in consideration of a random access point picture where arandom access can occur, and adjacent pictures thereof. When a randomaccess has occurred, since some skipped pictures and the metadatainformation are not decoded, the location of the metadata informationinserted into the video bitstream is significant in such a manner thatpictures having a decoding order after a random access point picture maybe decoded and then video-processed.

The bitstream generator 130 may generate the bitstream by inserting themetadata information into the location of the random access pointpicture and the location of a scene cut of a scene including one or morepictures having a decoding order after the random access point picture.In this case, the scene cut refers to a part where a scene including aplurality of pictures is switched to another scene including a pluralityof pictures. If the location of the random access point picturecorresponds to the location of a scene cut of an arbitrary scene, thebitstream generator 130 may substitute the metadata information of thescene corresponding to the scene cut for the metadata information to beinserted into the location of the random access point picture. As such,the same metadata information may not be repeatedly inserted.

The location of the scene cut may correspond to the location of thefirst picture in a display order among pictures belonging to each scene.The metadata information of an arbitrary scene may be inserted into thelocation of a scene cut corresponding to a previous scene of thearbitrary scene. As such, a delay due to decoding of the metadatainformation may be minimized or prevented by inserting the metadatainformation into the location of a scene cut corresponding to a previousscene of a scene to which the metadata information is applied, inconsideration of a time taken to decode the metadata information.

Based on the location of the random access point picture in the videobitstream, leading pictures preceding the random access point picture ina display order but following the random access point picture in adecoding order may be present. The leading pictures may be divided intonormally decodable leading pictures and undecodable leading pictures.Based on the location of the random access point picture, no decodableleading pictures may be present, or one or more decodable leadingpictures belonging to the same scene as or a different scene from therandom access point picture may be present.

When no leading pictures are present with respect to the random accesspoint picture and the location of the random access point picture is notthe location of a scene cut, the bitstream generator 130 may generatethe bitstream by inserting the metadata information of the scene towhich the random access point picture belongs, into the location of therandom access point picture.

When a plurality of decodable leading pictures are present with respectto the random access point picture, if all of the decodable leadingpictures belong to a different scene from the random access pointpicture, the bitstream generator 130 may generate the bitstream byinserting the metadata information of the scene to which the randomaccess point picture belongs, into the location of the random accesspoint picture, and inserting the metadata information of the scene towhich the decodable leading pictures belong, into the location of thefirst decodable leading picture in a display order.

When a plurality of decodable leading pictures are present with respectto the random access point picture, if all of the decodable leadingpictures belong to the same scene as the random access point picture,the bitstream generator 130 may generate the bitstream by inserting themetadata information of the scene including the decodable leadingpictures, into the location of the first decodable leading picture inthe display order. However, in consideration of a case where even thedecodable leading pictures are not decoded or are removed from the videobitstream, if the decodable leading pictures belong to the same scene asthe random access point picture, the bitstream generator 130 maygenerate the bitstream by inserting the metadata information into bothof the location of the first decodable leading picture in the displayorder and the location of the random access point picture. In addition,when a decodable leading picture is removed, the bitstream generator 130may move the metadata information included in the location of thepicture, to the location of the random access point picture belonging tothe same scene, because an undecodable leading picture and/or adecodable leading picture can be removed in a video decoding operationor a video output operation.

The bitstream generator 130 may generate the bitstream of the codedvideo data, which includes the metadata identification information. Whenthe video coder 110 has generated the metadata identificationinformation, the bitstream generator 130 may generate the videobitstream including the metadata identification information instead ofthe metadata information. Instead of directly including the metadatainformation, the metadata identification information is included in apredetermined location in the video bitstream to reduce a file size andto prevent overhead. However, when the bitstream generator 130 generatesthe video bitstream including the metadata identification information,parameters including predetermined values or conditions applicable whenthe metadata information is used for a video process may be included.

A metadata information database including the metadata information maybe transmitted from the video data generating apparatus 100 to the videodata processing apparatus 200 via an independent channel separately fromthe video bitstream including the metadata identification information.The metadata information database refers to at least one piece ofmetadata information stored in a predetermined storage space of thevideo data processing apparatus 200. The metadata information databasemay be transmitted from the video data generating apparatus 100 to thevideo data processing apparatus 200 at one time or in a distributedmanner, and stored in the video data processing apparatus 200. The videodata processing apparatus 200 may find the metadata information used fora video data process, from the metadata information database by usingthe metadata identification information. The metadata informationdatabase may be transmitted from the video data generating apparatus 100to the video data processing apparatus 200 before the video bitstream istransmitted, or together with the video bitstream via differentchannels.

FIG. 3B is a block diagram of the video data processing apparatus 200according to an embodiment. It will be understood by one of ordinaryskill in the art that the video data processing apparatus 200 mayinclude general-use hardware elements in addition to elementsillustrated in FIG. 3B.

The video data processing apparatus 200 may include a bitstream obtainer210, a video decoder 230, and a video processor 250.

The bitstream obtainer 210 may obtain a video bitstream. The bitstreamobtainer 210 may obtain the video bitstream received by the video dataprocessing apparatus 200, and transmit the video bitstream to the videodecoder 230.

The video decoder 230 may decode the video bitstream. The video decoder230 may extract metadata information usable for decoded video data whencoded video data is decoded and then video-processed, from the videobitstream. When a random access to the coded video data has occurred,the metadata information may be extracted from the decoded video dataafter a random access point picture in such a manner that pictureshaving a decoding order after the random access point picture may bedecoded and then video-processed.

The video processor 250 may obtain the metadata information used forvideo-processing of the pictures having the decoding order after therandom access point picture in the video bitstream.

The video processor 250 may obtain the metadata information based on thelocation of the random access point picture in the video bitstream andthe location of a scene cut of a scene including one or more pictureshaving a decoding order after the random access point picture. In thiscase, if the location of the random access point picture corresponds tothe location of a scene cut of an arbitrary scene, the video processor250 may use the metadata information of the scene corresponding to thescene cut, as the metadata information to be obtained from the locationof the random access point picture.

The location of the scene cut may correspond to the location of thefirst picture in a display order among pictures belonging to each scene.The metadata information of an arbitrary scene may be obtained from thelocation of a scene cut corresponding to a previous scene of thearbitrary scene. As such, a delay due to decoding of the metadatainformation may be minimized or prevented by inserting the metadatainformation into the location of a scene cut corresponding to a previousscene of a scene to which the metadata information is applied, inconsideration of a time taken to decode the metadata information.

Based on the location of the random access point picture, no decodableleading pictures may be present, or one or more decodable leadingpictures belonging to the same scene as or a different scene from therandom access point picture may be present.

When no leading pictures are present with respect to the random accesspoint picture and the location of the random access point picture is notthe location of a scene cut, the video processor 250 may obtain themetadata information of the scene to which the random access pointpicture belongs, based on the location of the random access pointpicture.

When a plurality of decodable leading pictures are present with respectto the random access point picture, if all of the decodable leadingpictures belong to a different scene from the random access pointpicture, the video processor 250 may obtain the metadata information ofthe scene to which the random access point picture belongs, based on thelocation of the random access point picture, and obtain the metadatainformation of the scene to which the decodable leading pictures belong,based on the location of the first decodable leading picture in adisplay order. When a plurality of decodable leading pictures arepresent with respect to the random access point picture, if all of thedecodable leading pictures belong to the same scene as the random accesspoint picture, the video processor 250 may obtain the metadatainformation of the scene to which the decodable leading pictures belong,based on the location of the first decodable leading picture in thedisplay order. However, in consideration of a case where even thedecodable leading pictures are not decoded or are removed from the videobitstream, if the decodable leading pictures belong to the same scene asthe random access point picture, since the metadata information may beincluded in both of the location of the first decodable leading picturein the display order and the location of the random access pointpicture, the video processor 250 may obtain the metadata informationbased on the two locations. In addition, when a decodable leadingpicture is removed, the metadata information included in the location ofthe picture may be moved to the location of the random access pointpicture belonging to the same scene. As such, in this case, the videoprocessor 250 may obtain the metadata information based on the locationof the random access point picture.

The video processor 250 may perform video-processing on the decodedvideo data among the pictures having a decoding order after the randomaccess point picture, based on the obtained metadata information.

When the video data generating apparatus 100 has transmitted the videobitstream by including metadata identification information in apredetermined location in the video bitstream, the video processor 250may obtain the metadata information from a metadata information databasebased on the metadata identification information. For example, themetadata identification information may be included in the locations ofall pictures belonging to each scene of the video bitstream. The videoprocessor 250 may obtain the metadata information mapped to the metadataidentification information, from the metadata information database. Themetadata information database may be received from the video datagenerating apparatus 100 via a channel different from a channel viawhich the video bitstream is received, before the video bitstream isreceived.

Examples of an operation of generating a bitstream of coded video dataand an operation of processing the bitstream of the coded video datawill now be described. A video bitstream using metadata identificationinformation in consideration of a random access will be described indetail with reference to FIGS. 4 and 5, and a video bitstreamconsidering an optimal location of metadata information in the videobitstream in consideration of a random access will be described indetail with reference to FIGS. 6A to 6C.

FIG. 4 is a schematic diagram for describing a method of generating andprocessing a bitstream of coded video data by using metadataidentification information, according to an embodiment.

Referring to FIG. 4, the video data generating apparatus 100 maytransmit a video bitstream to the video data processing apparatus 200.To prevent loss of metadata information of each scene used for a videoprocess even when a random access has occurred in the video dataprocessing apparatus 200, the video bitstream may include metadataidentification information in the locations of all pictures belonging toeach scene of the video bitstream. The metadata identificationinformation may include an identifier (ID) of the metadata informationand location information of the metadata information. Instead ofdirectly including the metadata information, the metadata identificationinformation is included in the locations of all pictures belonging toeach scene to reduce a file size and to prevent overhead. The metadataidentification information may be used to search a metadata informationdatabase for the metadata information.

Although the metadata identification information may be included in thelocations of all pictures belonging to each scene, to further reduce afile size, the number of times that the metadata identificationinformation is transmitted may be reduced. For example, the metadataidentification information may be transmitted every predetermined numberof pictures among pictures belonging to the same scene.

The metadata information may be transmitted from the video datagenerating apparatus 100 to the video data processing apparatus 200 viaan independent channel separately from the video bitstream including themetadata identification information. A part of or the whole metadatainformation database having all metadata information may be transmittedfrom the video data generating apparatus 100 to the video dataprocessing apparatus 200. The metadata information may be transmittedvia a channel different from a channel via which the video bitstream istransmitted, before the video bitstream is transmitted. For example, themetadata information may be transmitted via a safe channel used totransmit syntax data such as a sequence parameter set (SPS) or pictureparameter set (PPS). Some or all metadata information may beperiodically transmitted with a long term. The number of times that themetadata identification information is transmitted may be greater thanthe number of times that the metadata information database searchablefor the metadata information is transmitted.

FIGS. 5A and 5B are tables showing message formats for transmittingmetadata identification information.

The message format of FIG. 5A may include both the metadataidentification information and the metadata information, and aconditional statement in the message format may be used to determinewhether to include the metadata information or not. In FIG. 5A, themetadata information may be included and transmitted if the value of a“meta_data_info_present_flag” is “true”, and only the metadataidentification information may be included and transmitted if the valueof the “meta_data_info_present_flag” is “false”. Accordingly, when themetadata identification information is included and transmitted in eachpicture, the value of the “meta_data_info_present_flag” may be set to“false”.

Unlike the message format of FIG. 5A which uses a conditional statementto indicate the type of transmitted data, the message format of FIG. 5Bseparately defines a message format for transmitting the metadatainformation and a message format for transmitting the metadataidentification information. In FIG. 5B, a “meta_data_info” messageformat may transmit the metadata information, and a “meta_data_pointer”message format may transmit the metadata identification information.Accordingly, when the metadata identification information is includedand transmitted in each picture, the “meta_data_pointer” message formatmay be used.

FIG. 6A is a schematic diagram for describing a method of generating andprocessing a bitstream of coded video data in consideration of anoptimal location of metadata information in the video bitstream,according to an embodiment.

Referring to FIG. 6A, a part of video data having different display anddecoding orders is shown. In the display order or an output order, thevideo data corresponds to pictures from the 26^(th) picture to the32^(nd) picture, and may be regarded as a sequence of pictures to besequentially displayed from the 26^(th) picture. However, in thedecoding order, a picture corresponding to the 27^(th) picture in thedisplay order has the 24^(th) decoding order which is the earliest, anda picture corresponding to the 32^(nd) picture in the display order hasthe 34^(th) decoding order which is the latest.

As illustrated in FIG. 6A, assuming that a random access has occurred ina picture corresponding to the 31^(st) picture in the display order, arandom access point picture is the picture corresponding to the 31^(st)picture in the display order. Since the picture corresponding to the31^(st) picture in the display order has the 28^(th) decoding order,only pictures after the 28^(th) decoding order may be decoded.Accordingly, the 26^(th) and 27^(th) pictures in the display order havethe 27^(th) and 24^(th) decoding orders and thus may not be decoded.

Referring to FIG. 6A, the 28^(th), 29^(th) and 30^(th) pictures in thedisplay order precede the 31^(st) picture, which is the random accesspoint picture, in the display order but follow the 31^(st) picture inthe decoding order, and thus correspond to leading pictures and, moreparticularly, to decodable leading pictures. Pictures following therandom access point picture both in the display order and in thedecoding order are called trailing pictures. Referring to FIG. 6A, the32^(nd) picture in the display order follows the 31^(st) picture, whichis the random access point picture, both in the display order and in thedecoding order, and thus corresponds to a trailing picture. When theabove-described video data is coded to generate a video bitstream, thevideo bitstream into which metadata information corresponding to eachscene is inserted may be generated in consideration of a random accessas described below.

Referring to FIG. 6A, since a random access has occurred in the picturehaving the 28^(th) decoding order, metadata information of the picturesafter the 28^(th) decoding order should be inserted when the videobitstream is generated. As illustrated in FIG. 6A, the 29th, 30^(th),and 31^(st) pictures in the decoding order are decodable leadingpictures and correspond to a first scene different from a second sceneto which the random access point picture belongs, and thus firstmetadata information m1 should be inserted. The 28^(th) and 34^(th)pictures in the decoding order correspond to the second scene and thussecond metadata information m2 should be inserted. However, when thevideo bitstream is generated, since the pictures are arranged in thedecoding order irrespective of the display order or a scene order,metadata information may be preferentially inserted into the location ofa picture which firstly requires metadata information in considerationof the decoding order, but the already-inserted metadata informationshould not be repeatedly included.

As illustrated in FIG. 6A, when a random access has occurred and thusthe picture having the 28^(th) decoding order serves as the randomaccess point picture, the second metadata information m2 of the secondscene to which the random access point picture belongs may be insertedinto the location of the random access point picture. In this case, thelocation of the random access point picture may be a locationimmediately before or after the random access point picture, and thesecond metadata information m2 may be inserted in front of the randomaccess point picture as illustrated in FIG. 6A.

Then, the pictures having the 29^(th), 30^(th) and 31^(st) decodingorders correspond to the first scene, and the first metadata informationm1 of the first scene may be inserted into the location of a scene cutof the first scene. In this case, the location of the scene cut of thefirst scene may be a location immediately before or after the picturesbelonging to the first scene and, more particularly, the location of thefirst picture in the display order among the pictures belonging to thefirst scene. As illustrated in FIG. 6A, the picture having the 30^(th)decoding order is the first picture in the display order among thepictures belonging to the first scene, and thus the first metadatainformation m1 may be inserted in front of the picture having the30^(th) decoding order. The pictures having the 29^(th) and 31^(st)decoding orders may use the first metadata information m1 inserted infront of the picture having the 30^(th) decoding order, and thus thefirst metadata information m1 does not need to be repeatedly inserted.

Thereafter, metadata information of a scene to which each of picturesafter the 32^(nd) decoding order belongs may be inserted into thelocation of a scene cut of the scene, but the already-inserted metadatainformation is not repeatedly inserted. As illustrated in FIG. 6A, thepicture having the 34^(th) decoding order corresponds to the secondscene but the second metadata information m2 has been already insertedin front of the random access point picture. Thus, the second metadatainformation m2 is not repeatedly inserted.

When a random access has occurred in the video data processing apparatus200, a video bitstream including metadata information and generated inconsideration of a random access may be processed based on a reverseoperation of an operation of generating the video bitstream. In otherwords, the video data processing apparatus 200 may obtain metadatainformation based on a location in the video bitstream, into which themetadata information of each scene to which decodable pictures amongpictures having a decoding order after a random access point picturebelong is initially inserted, and perform video-processing on decodedpictures based on the obtained metadata information.

FIG. 6B is a schematic diagram for describing a method of generating andprocessing a bitstream of coded video data in consideration of anoptimal location of metadata information in the video bitstream,according to another embodiment.

Display and decoding orders of a part of video data illustrated in FIG.6B are the same as those of the part of the video data illustrated inFIG. 6A, except that pictures corresponding to a zeroth scene andpictures corresponding to a first scene differ. In other words, FIG. 6Bshows a case where decodable leading pictures belong to a plurality ofscenes different from a scene to which a random access point picturebelongs. A description is now given of the difference from the method ofFIG. 6A in a case where a picture corresponding to the 28^(th) picturein a display order belongs to the zeroth scene other than the firstscene.

As illustrated in FIG. 6B, since the random access point picture is apicture corresponding to the 31^(st) picture in the display order andthe picture corresponding to the 31^(st) picture in the display orderhas the 28^(th) decoding order, only pictures after the 28^(th) decodingorder may be decoded. The 28^(th), 29^(th) and 30^(th) pictures in thedisplay order correspond to decodable leading pictures. The 32^(nd)picture in the display order corresponds to a trailing picture. When theabove-described video data is coded to generate a video bitstream, thevideo bitstream into which metadata information corresponding to eachscene is inserted may be generated in consideration of a random accessas described below.

Referring to FIG. 6B, since a random access has occurred in the picturehaving the 28^(th) decoding order, metadata information of the picturesafter the 28^(th) decoding order should be inserted when the videobitstream is generated. The 29^(th), 30^(th), and 31^(st) pictures inthe decoding order are decodable leading pictures. The 30^(th) picturesin the decoding order corresponds to the zeroth scene, and thus zerothmetadata information m0 should be inserted when the video bitstream isgenerated. The 29^(th) and 31^(st) pictures in the decoding ordercorrespond to the first scene, and thus first metadata information m1should be inserted when the video bitstream is generated. The 28^(th)and 34^(th) pictures in the decoding order correspond to a second sceneand thus second metadata information m2 should be inserted.

As illustrated in FIG. 6B, when a random access has occurred and thusthe picture having the 28^(th) decoding order serves as the randomaccess point picture, the second metadata information m2 of the secondscene to which the random access point picture belongs may be insertedinto the video bitstream in front of the random access point picture.

Then, the picture having the 29^(th) decoding order corresponds to thefirst scene, and the first metadata information m1 of the first scenemay be inserted into the location of a scene cut of the first scene. Asillustrated in FIG. 6B, the picture having the 29^(th) decoding order isthe first picture in the display order among the pictures belonging tothe first scene, and thus the first metadata information m1 may beinserted into the video bitstream in front of the picture having the29^(th) decoding order.

Thereafter, the picture having the 30^(th) decoding order corresponds tothe zeroth scene, and the zeroth metadata information m0 of the zerothscene may be inserted into the video bitstream. In this case, since onlythe picture having the 30^(th) decoding order is decodable among thepictures belonging to the zeroth scene as illustrated in FIG. 6B, thezeroth metadata information m0 may be inserted into video bitstream infront of the picture having the 30^(th) decoding order.

Then, the picture having the 31^(st) decoding order may use the firstmetadata information m1 already inserted in front of the picture havingthe 29^(th) decoding order, and thus the first metadata information m1does not need to be repeatedly inserted.

Thereafter, metadata information of a scene to which each of picturesafter the 32^(nd) decoding order belongs may be inserted into thelocation of a scene cut of the scene, but the already-inserted metadatainformation is not repeatedly inserted. As illustrated in FIG. 6B, thepicture having the 34^(th) decoding order corresponds to the secondscene but the second metadata information m2 has been already insertedin front of the random access point picture. Thus, the second metadatainformation m2 is not repeatedly inserted.

When a random access has occurred in the video data processing apparatus200, a video bitstream including metadata information and generated inconsideration of a random access may be processed based on a reverseoperation of an operation of generating the video bitstream. In otherwords, the video data processing apparatus 200 may obtain metadatainformation based on a location into which the metadata information ofeach scene to which decodable pictures among pictures having a decodingorder after a random access point picture belong is initially inserted,and perform video-processing on decoded pictures based on the obtainedmetadata information.

FIG. 6C is a schematic diagram for describing a method of generating andprocessing a bitstream of coded video data in consideration of anoptimal location of metadata information in the video bitstream,according to another embodiment.

Referring to FIG. 6C, a part of video data is shown. The video datacorresponds to pictures from the 26^(th) picture to the 36^(th) picturein a display order, and may be regarded as a sequence of pictures to besequentially displayed from the 26^(th) picture. However, a decodingorder differs from the display order as indicated by arrows showingrelationships between pictures.

As illustrated in FIG. 6C, assuming that a random access has occurred ina picture corresponding to the 35^(th) picture in the display order, arandom access point picture is the picture corresponding to the 35^(th)picture in the display order. Pictures corresponding to the 26^(th) and27^(th) pictures in the display order precede the random access pointpicture in a coding order, and thus do not correspond to a videobitstream considering a random access to the 35^(th) picture. Referringto FIG. 6C, the video bitstream considering a random access to the35^(th) picture may correspond to only pictures having a decoding orderafter the 35^(th) picture. That is, when the pictures arranged in thedisplay order are re-arranged in the decoding order, the 35^(th),31^(st), 29^(th), 28^(th), 30^(th), 33^(rd), 32^(nd), 34^(th), and36^(th) pictures may correspond to the video bitstream considering arandom access to the 35^(th) picture. However, the 28^(th) to 30^(th)pictures in the display order are undecodable leading pictures, and thusmetadata information of the 28^(th) to 30^(th) pictures does not need tobe inserted into the video bitstream.

FIG. 6C shows two methods about locations of the video bitstream intowhich first metadata information m1 of the 32^(nd), 33^(rd), and 34^(th)pictures belonging to a first scene among decodable leading pictures isinserted.

First, a video bitstream of option 1 shows a method of insertingmetadata information into the location of the first picture in thedisplay order among pictures belonging to each scene. Based on thismethod, since the 32^(nd) picture among the 32^(nd), 33^(rd), and34^(th) pictures belonging to the first scene corresponds to the firstpicture in the display order, the first metadata information m1 isinserted in front of the 32^(nd) picture. The above-described methods ofFIGS. 6A and 6B correspond to the method of inserting metadatainformation corresponding to each scene into the location of the firstpicture in the display order among pictures belonging to the scene.

Second, a video bitstream of option 2 shows a method of insertingmetadata information into the location of the first picture in a codingorder among pictures belonging to each scene. Based on this method,since the 33^(rd) picture among the 32^(nd), 33^(rd), and 34^(th)pictures belonging to the first scene corresponds to the first picturein the decoding order, the first metadata information m1 is inserted infront of the 33^(rd) picture. The above-described methods of FIGS. 6Aand 6B may follow the method of inserting metadata informationcorresponding to each scene into the location of the first picture inthe decoding order among pictures belonging to the scene.

When a video bitstream is generated and processed in consideration of arandom access, a method of transmitting metadata identificationinformation in an optimal location in the bitstream may be used bycombining the method of reducing a bitrate by using metadataidentification information, which is described above in relation toFIGS. 4 and 5, and a method of considering an optimal location in avideo bitstream into which metadata information is to be inserted, whichis described above in relation to FIGS. 6A to 6C.

FIG. 7A is a flowchart of a coded video data generating method accordingto an embodiment. Although not provided herein, the above descriptionsof the video data generating apparatus 100 may be equally applied to thecoded video data generating method.

In operation 710, the video data generating apparatus 100 may code videodata. The video data generating apparatus 100 may generate coded videodata by coding input video in a coding order.

In operation 720, the video data generating apparatus 100 may generatemetadata information to be inserted into a starting part of each sceneand used for a video process, or metadata information used forvideo-processing of pictures having a decoding order after a randomaccess point picture. The video data generating apparatus 100 maygenerate metadata information usable when the coded video data isdecoded and then video-processed. The metadata information may beprepared in such a manner that pictures having a decoding order after arandom access point picture may be decoded and then video-processed evenwhen a random access to the coded video data has occurred.

To prevent loss of metadata information of each scene, which is used fora video process, even when a random access has occurred in the videodata processing apparatus 200, the video data generating apparatus 100may generate metadata identification information to be included in thelocations of all pictures belonging to each scene of the videobitstream.

In operation 730, the video data generating apparatus 100 may generate abitstream of the coded video data, which includes the metadatainformation or the metadata identification information. The video datagenerating apparatus 100 may generate the video bitstream including themetadata information by inserting the metadata information into astarting part of each scene, or inserting the metadata information intoan appropriate location in consideration of a random access pointpicture where a random access can occur, and adjacent pictures thereof.

The video data generating apparatus 100 may generate the bitstream byinserting the metadata information into the location of the randomaccess point picture and the location of a scene cut of a sceneincluding one or more pictures having a decoding order after the randomaccess point picture. In this case, if the location of the random accesspoint picture corresponds to the location of a scene cut of an arbitraryscene, the video data generating apparatus 100 may substitute themetadata information of the scene corresponding to the scene cut for themetadata information to be inserted into the location of the randomaccess point picture. As such, the same metadata information may not berepeatedly inserted.

The location of the scene cut may correspond to the location of thefirst picture in a display order among pictures belonging to each scene.The metadata information of an arbitrary scene may be inserted into thelocation of a scene cut corresponding to a previous scene of thearbitrary scene. As such, a delay due to decoding of the metadatainformation may be minimized or prevented by inserting the metadatainformation into the location of a scene cut corresponding to a previousscene of a scene to which the metadata information is applied, inconsideration of a time taken to decode the metadata information.

Based on the location of the random access point picture, no decodableleading pictures may be present, or a plurality of decodable leadingpictures belonging to the same scene as or a different scene from therandom access point picture may be present.

When no leading pictures are present with respect to the random accesspoint picture and the location of the random access point picture is notthe location of a scene cut, the video data generating apparatus 100 maygenerate the bitstream by inserting the metadata information of thescene to which the random access point picture belongs, into thelocation of the random access point picture.

When a plurality of decodable leading pictures are present with respectto the random access point picture, if all of the decodable leadingpictures belong to a different scene from the random access pointpicture, the video data generating apparatus 100 may generate thebitstream by inserting the metadata information of the scene to whichthe random access point picture belongs, into the location of the randomaccess point picture, and inserting the metadata information of thescene to which the decodable leading pictures belong, into the locationof the first decodable leading picture in the display order.

When a plurality of decodable leading pictures are present with respectto the random access point picture, if all of the decodable leadingpictures belong to the same scene as the random access point picture,the video data generating apparatus 100 may generate the bitstream byinserting the metadata information of the scene including the decodableleading pictures, into the location of the first decodable leadingpicture in the display order. However, in consideration of a case whereeven the decodable leading pictures are not decoded or are removed fromthe video bitstream, if the decodable leading pictures belong to thesame scene as the random access point picture, the video data generatingapparatus 100 may generate the bitstream by inserting the metadatainformation into both of the location of the first decodable leadingpicture in the display order and the location of the random access pointpicture. In addition, when a decodable leading picture is removed, thevideo data generating apparatus 100 may move the metadata informationincluded in the location of the picture, to the location of the randomaccess point picture belonging to the same scene.

The video data generating apparatus 100 may generate the bitstream ofthe coded video data, which includes the metadata identificationinformation. When the video data generating apparatus 100 has generatedthe metadata identification information, the video data generatingapparatus 100 may generate the video bitstream including the metadataidentification information instead of the metadata information. Thevideo data generating apparatus 100 may generate the video bitstream insuch a manner that the metadata identification information is includedin a predetermined location in the video bitstream. A metadatainformation database including the metadata information may betransmitted from the video data generating apparatus 100 to the videodata processing apparatus 200 via an independent channel separately fromthe video bitstream including the metadata identification information.

FIG. 7B is a flowchart of a coded video data processing method accordingto an embodiment. Although not provided herein, the above descriptionsof the video data processing apparatus 200 may be equally applied to thecoded video data processing method.

In operation 810, the video data processing apparatus 200 may obtain avideo bitstream. The video data processing apparatus 200 may decode theobtained video bitstream. The video data processing apparatus 200 mayextract metadata information usable for decoded video data when codedvideo data is decoded and then video-processed, from the videobitstream. When a random access to the coded video data has occurred,the metadata information may be extracted from the decoded video dataafter a random access point picture in such a manner that pictureshaving a decoding order after the random access point picture may bedecoded and then video-processed.

In operation 820, the video data processing apparatus 200 may obtain themetadata information used for video-processing of the pictures havingthe decoding order after the random access point picture in the videobitstream.

The video data processing apparatus 200 may obtain the metadatainformation based on the location of the random access point picture inthe video bitstream and the location of a scene cut of a scene includingone or more pictures having a decoding order after the random accesspoint picture. In this case, if the location of the random access pointpicture corresponds to the location of a scene cut of an arbitraryscene, the video data processing apparatus 200 may use the metadatainformation of the scene corresponding to the scene cut, as the metadatainformation to be obtained from the location of the random access pointpicture.

The location of the scene cut may correspond to the location of thefirst picture in a display order among pictures belonging to each scene.The metadata information of an arbitrary scene may be obtained from thelocation of a scene cut corresponding to a previous scene of thearbitrary scene. As such, a delay due to decoding of the metadatainformation may be minimized or prevented by inserting the metadatainformation into the location of a scene cut corresponding to a previousscene of a scene to which the metadata information is applied, inconsideration of a time taken to decode the metadata information.

Based on the location of the random access point picture, no decodableleading pictures may be present, or one or more decodable leadingpictures belonging to the same scene as or a different scene from therandom access point picture may be present.

When no leading pictures are present with respect to the random accesspoint picture and the location of the random access point picture is notthe location of a scene cut, the video data processing apparatus 200 mayobtain the metadata information of the scene to which the random accesspoint picture belongs, based on the location of the random access pointpicture.

When a plurality of decodable leading pictures are present with respectto the random access point picture, if all of the decodable leadingpictures belong to a different scene from the random access pointpicture, the video data processing apparatus 200 may obtain the metadatainformation of the scene to which the random access point picturebelongs, based on the location of the random access point picture, andobtain the metadata information of the scene to which the decodableleading pictures belong, based on the location of the first decodableleading picture in the display order.

When a plurality of decodable leading pictures are present with respectto the random access point picture, if all of the decodable leadingpictures belong to the same scene as the random access point picture,the video data processing apparatus 200 may obtain the metadatainformation of the scene to which the decodable leading pictures belong,based on the location of the first decodable leading picture in thedisplay order. However, in consideration of a case where even thedecodable leading pictures are not decoded or are removed from the videobitstream, if the decodable leading pictures belong to the same scene asthe random access point picture, since the metadata information may beincluded in both of the location of the first decodable leading picturein the display order and the location of the random access pointpicture, the video data processing apparatus 200 may obtain the metadatainformation based on the two locations. In addition, when a decodableleading picture is removed, the metadata information included in thelocation of the picture may be moved to the location of the randomaccess point picture belonging to the same scene. As such, in this case,the video data processing apparatus 200 may obtain the metadatainformation based on the location of the random access point picture.

When the video data generating apparatus 100 has transmitted the videobitstream by including metadata identification information in apredetermined location in the video bitstream, the video data processingapparatus 200 may obtain the metadata information from a metadatainformation database based on the metadata identification information.For example, the metadata identification information may be included inthe locations of all pictures belonging to each scene of the videobitstream. The video data processing apparatus 200 may obtain themetadata information mapped to the metadata identification information,from the metadata information database. The metadata informationdatabase may be received from the video data generating apparatus 100via a channel different from a channel via which the video bitstream isreceived, before the video bitstream is received.

In operation 830, the video data processing apparatus 200 may performvideo-processing on the decoded video data among the pictures having thedecoding order after the random access point picture, based on theobtained metadata information.

The embodiments of the present invention can be written as computerprograms and can be implemented in general-use digital computers thatexecute the programs using a non-transitory computer-readable recordingmedium. Examples of the non-transitory computer-readable recordingmedium include magnetic storage media (e.g., ROM, floppy disks, harddisks, etc.) and optical recording media (e.g., CD-ROMs, or DVDs).

While the present invention has been particularly shown and describedwith reference to embodiments thereof, it will be understood by one ofordinary skill in the art that various changes in form and details maybe made therein without departing from the spirit and scope of theinvention as defined by the following claims. The exemplary embodimentsshould be considered in a descriptive sense only and not for purposes oflimitation. Therefore, the scope of the invention is defined not by thedetailed description of the invention but by the following claims, andall differences within the scope will be construed as being included inthe present invention.

1. A coded video data processing method comprising: obtaining abitstream of coded video data; obtaining metadata information used forvideo-processing of pictures having a decoding order after a randomaccess point picture in the bitstream; and performing video-processingon decoded video data among the pictures having the decoding order afterthe random access point picture, based on the metadata information. 2.The coded video data processing method of claim 1, wherein the obtainingof the metadata information comprises: obtaining metadata identificationinformation corresponding to the metadata information from apredetermined location in the bitstream; and obtaining the metadatainformation mapped to the obtained metadata identification information,from a metadata information database.
 3. The coded video data processingmethod of claim 2, further comprising obtaining the metadata informationdatabase via a channel different from a channel via which the bitstreamis obtained.
 4. The coded video data processing method of claim 1,wherein the obtaining of the metadata information comprises obtainingthe metadata information based on a location of the random access pointpicture in the bitstream and a location of a scene cut of a scenecomprising one or more pictures having a decoding order after the randomaccess point picture.
 5. The coded video data processing method of claim4, wherein the obtaining of the metadata information comprises, if therandom access point picture and decodable leading pictures belong to asame scene, obtaining metadata information of the scene to which therandom access point picture and the decodable leading pictures belong,based on a location of a first decodable leading picture in a displayorder.
 6. The coded video data processing method of claim 4, wherein theobtaining of the metadata information comprises, if the random accesspoint picture and decodable leading pictures belong to different scenes,obtaining metadata information of the scene to which the random accesspoint picture belongs and metadata information of the scene to which thedecodable leading pictures belong, based on a location of the randomaccess point picture and a location of a first decodable leading picturein a display order.
 7. The coded video data processing method of claim4, wherein the location of the scene cut corresponds to a location of afirst picture in a display order among pictures belonging to each scene.8. A coded video data generating method comprising: coding video data;generating metadata information used for video-processing of pictureshaving a decoding order after a random access point picture; andgenerating a bitstream of the coded video data, the bitstream comprisingthe metadata information or metadata identification informationcorresponding to the metadata information.
 9. The coded video datagenerating method of claim 8, wherein the generating of the bitstreamcomprises generating the bitstream by inserting the metadataidentification information into a predetermined location in thebitstream.
 10. The coded video data generating method of claim 9,further comprising transmitting the bitstream comprising the metadataidentification information, and a metadata information databasecomprising the generated metadata information, via different channels.11. The coded video data generating method of claim 8, wherein thegenerating of the bitstream comprises generating the bitstream byinserting the metadata information into a location of the random accesspoint picture and a location of a scene cut of a scene comprising one ormore pictures having a decoding order after the random access pointpicture.
 12. The coded video data generating method of claim 11, whereinthe generating of the bitstream comprises, if the random access pointpicture and decodable leading pictures belong to a same scene,generating the bitstream by inserting metadata information of the sceneto which the random access point picture and the decodable leadingpictures belong, into a location of a first decodable leading picture ina display order.
 13. The coded video data generating method of claim 11,wherein the generating of the bitstream comprises, if the random accesspoint picture and decodable leading pictures belong to different scenes,generating the bitstream by inserting metadata information of the sceneto which the random access point picture belongs, into a location of therandom access point picture, and inserting metadata information of thescene to which the decodable leading pictures belong, into a location ofa first decodable leading picture in a display order.
 14. The codedvideo data generating method of claim 11, wherein the location of thescene cut corresponds to a location of a first picture in a displayorder among pictures belonging to each scene.
 15. A non-transitorycomputer-readable recording medium having recorded thereon a computerprogram for executing the method of claim
 1. 16. A video data processingapparatus comprising: a bitstream obtainer for obtaining a bitstream ofcoded video data; a video decoder for decoding the bitstream; and avideo processor for obtaining metadata information used forvideo-processing of pictures having a decoding order after a randomaccess point picture in the bitstream, and performing video-processingon the decoded video data among the pictures having the decoding orderafter the random access point picture, based on the metadatainformation.
 17. The video data processing apparatus of claim 16,wherein the video processor obtains metadata identification informationcorresponding to the metadata information from a predetermined locationin the bitstream, and obtains the metadata information mapped to theobtained metadata identification information, from a metadatainformation database.
 18. The video data processing apparatus of claim16, wherein the video processor obtains the metadata information basedon a location of the random access point picture in the bitstream and alocation of a scene cut of a scene comprising one or more pictureshaving a decoding order after the random access point picture.
 19. Avideo data generating apparatus comprising: a video coder for codingvideo data and generating metadata information used for video-processingof pictures having a decoding order after a random access point picture;and a bitstream generator for generating a bitstream of the coded videodata, the bitstream comprising the metadata information or metadataidentification information corresponding to the metadata information.20. The coded video data generating apparatus of claim 19, wherein thebitstream generator generates the bitstream by inserting the metadatainformation into a location of the random access point picture and alocation of a scene cut of a scene comprising one or more pictureshaving a decoding order after the random access point picture.